This invention relates to a cutting tool bit for single-sided use, having a central mounting hole, a planar bottom face as a support face and a top face which is located opposite the bottom face and the center of which is depressed with respect to its edge zones. The top face has chip breaking elements and forms cutting edges with the lateral faces of the tool bit. The cutting tool bit is tightened in a cutting tool by a clamping element and it utilized for machining steel and iron workpieces.
Cutting tool bits of the above-outlined type having diverse chip breaking elements are known. Thus, cutting tool bits are widely used which have uniformly shaped chip breaker grooves extending peripherally on the top face of the tool bit. Further, cutting tool bits are known in which the cutting edges slope downwardly or upwardly from the corners to the middle of the cutting edge and wherein parts of the top face function as a chip breaker element. It is a disadvantage of the known cutting tool bits that the quality of the chip breaking depends from the cutting depth; an optimal chip breaking effect is, as a rule, achieved when the cutting depth is approximate 1/4 of the length of the cutting edge. By increasing the feeding speed, it is possible, to be sure, to improve the chip breaking effect even in case of greater cutting depth. In a substantial number of machining operations (for example, turning in shoulder zones), however, it is not feasible to increase the feeding speed.